JPH0442720Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a heating device in a hot isostatic press.

(Prior art) An object to be molded, such as various metal powders, is set in a sealed pressure vessel, and the pressure of the pressure medium is increased by pressurized fluid supplied into the pressure vessel, and by a heating device installed in the pressure vessel. The isostatic press, which hot compression molds a molded object under isostatic pressure through heating, is a so-called
Needless to say, it is known as a HIP device, and the use of a cylindrical self-supporting single-stage heater and a convection promoting cylinder as the heating device is also disclosed in Japanese Utility Model Application Publication No. 59-70199. It is a place.
That is, as shown in FIGS. 3 and 4, it consists of a pressure vessel 1 that is open at both upper and lower ends, and an upper lid 2 and a lower lid 3 that are removably fitted tightly into the openings at both upper and lower ends, and are not shown. However, by providing a pressure medium supply/discharge line using pressurized fluid on the upper lid and/or lower lid side, the pressure medium is supplied into the pressure vessel 1 and the support base on the lower lid 3 is provided. At the same time, a heat insulating layer 5 is arranged in the pressure vessel 1, and a cylindrical self-supporting single-stage heater 6 is placed inside the heat insulating layer 5, and convection is promoted inside the heater 6. Both of the cylindrical bodies 11 are fixed with an electric insulator 8 whose cylindrical lower end is provided at the lower end of the heat insulating layer 5, and are erected in a layered manner inside and outside. As shown in FIG. 4, the element structure is such that slits 10 are formed alternately from both ends of the cylindrical body in the vertical direction, and the lower end of the slits 10 are embedded in the electrical insulator 8 described above. Furthermore, a guide ring 9 made of an electrically insulating material is fitted to the upper edge of the pressure vessel 1, and a convection promoting cylinder 11 provided to promote uniformity of heat distribution in the vertical direction within the pressure vessel 1 is formed of a cylindrical shape. The convection promoting cylinder 11 is generally made of a heat-resistant alloy such as Mo or its alloy, stainless steel, or a Ni-based alloy. Single stage heater 6 across the direction
However, when using a multistage heater 6 system with two or more stages in the vertical direction, the convection promoting cylinder 11 is not particularly necessary because the uniformity of heat distribution is good. It's something you don't do.

(Problems to be Solved by the Invention) The heating device using the single-stage heater 6 and the convection promoting cylinder 11 described above has a problem in that thermal deformation inevitably occurs as it is continuously used. . That is, in the heater 6 having a large number of cut slits 10, the rigidity is particularly poor and the shaping strength is insufficient, so as the cylindrical fence-like element is used continuously, the center part in the vertical direction becomes maximum outward. In contrast, the upper and lower edges are constrained by electrical insulators 8 and guide rings 9, so that the entire element is thermally deformed into an hourglass shape, and the convection promoting cylinder 11 is a cylinder with no notches. Despite its shape, the cylinder is distorted into an elliptical cylinder. At most, the deformation of both is slight, but if the deformation progresses, they will eventually come into contact, causing electrical leakage, metal welding, etc., and making the product unusable. Furthermore, even in the case of a multi-stage heater that does not use the convection promoting cylinder 11, the heater 6 may deform and come into contact with the outer heat insulating layer 5, or the elements may come into contact with each other, resulting in the same unusability. be. Replacing the heater 6 and the convection promoting cylinder 11 while the deformation is slight will not only shorten their service life, but also require complicated replacement methods and labor, which will reduce the cost and work efficiency. It is also disadvantageous in terms of

(Means for Solving the Problems) In order to solve the problems in the conventional heating devices, the present invention increases the vertical axial section modulus of the heater and the convection promoting cylinder, thereby preventing thermal deformation. By increasing the resistance force, thermal deformation can be effectively prevented. A hot isostatic press comprising an upper lid and a lower lid that are removably fitted tightly together, and a cylindrical self-supporting single-stage heater and a convection promoting cylinder are disposed within the pressure vessel via a heat insulating layer. In the heating device, an uneven curved surface whose cross section is substantially chevron-shaped or wavy is formed as a rigid reinforcing surface along the vertical direction on the wall surface extending in the vertical direction of the heater and the convection promoting cylinder. .

(Function) According to the technical means of the present invention, as shown in FIGS. 1 and 2 showing the heater and FIG. 2 showing the convection promoting cylinder,
In the heater 6, the upper edge 6a of the cylindrical main body
As shown in the A-A cross section of the figure, an uneven curved surface 12 whose cross section is approximately chevron-shaped is formed on the vertically elongated wall surface 6c of the element in which slits 10 are alternately cut out from the lower edge 6b side. is formed along the vertical direction, and the convection promoting cylinder 1
In No. 1, the cylindrical wall surface 11c extending in the vertical direction of the cylindrical main body has a substantially wavy uneven curved surface 13 formed continuously along the vertical direction over the entire circumference in its cross section. Unlike the simple flat wall structure of the conventional heater 6 and convection promoting cylinder 11, the presence of these uneven curved surfaces 12 and 13 increases the vertical axial section modulus and significantly improves the overall rigidity. By doing so, the resistance to thermal deformation is significantly increased, and the deformation of the drum shape in the heater 6 and the deformation of the elliptical shape in the convection promoting cylinder 11, which occur in the conventional case during continuous use, can be effectively prevented. This improves its durability and enables trouble-free and safe operation for long periods of time.

(Embodiment) A suitable embodiment of the heating device according to the present invention will be described with reference to FIGS. 1, 2 and 2. The pressure vessel 1, which constitutes the main body of the hot isostatic press used in the present invention, and the upper cover 2 and lower cover 3, which are removably fitted tightly into the upper and lower opening ends of the pressure vessel 1, are the same as the conventional example shown in FIG. It is the same as that in various hot isostatic presses, and its illustration is omitted, and FIG. 3 will be used instead as one of the embodiments.

In the embodiment of the cylindrical self-supporting heater 6 shown in FIG. 1, each vertically long wall surface 6c extending vertically through the slit 10 has a chevron-shaped cross section and an uneven curved surface 12 formed along the vertical direction. It is free to arrange one or more in parallel depending on the width of the wall surface 16c. In addition, in the convection promoting cylinder 11 shown in FIG. 2, from the upper edge 11a to the lower edge 1
As an example, a wavy uneven curved surface 13 is continuously and repeatedly formed on the entire circumferential surface of the cylindrical wall surface 11c extending over 1b, so that the entire wall surface 11c has an accordion cylindrical shape. When installing the heater 6 and the convection promoting cylinder 11 in the pressure vessel 1, for example, an electric insulator is provided at the lower end of the heat insulating layer 5, as in the prior art shown in FIG. 8, the lower ends of both 6 and 11 are fixed for use.

(Effects of the Present Invention) The heating device of the present invention is excellent in that it effectively prevents thermal deformation of the heater and convection promoting cylinder that occurs in conventional heating devices. That is, in the present invention, in both the single-stage cylindrical self-supporting heater 6 and the convection promoting cylinder 11, the vertically extending wall surfaces 6c and 11c are provided with uneven curved surfaces 12 whose cross sections are approximately mountain-shaped or wave-shaped. 13 are formed along the vertical direction, the overall rigidity is significantly improved, thereby increasing the resistance to deformation due to heat and effectively preventing the deformation of both into an hourglass or elliptical shape. This eliminates the trouble of unusability due to contact caused by deformation between the two, electrical leakage, etc., resulting in increased durability, easier maintenance, and increased safety, and this is necessary. The structure is simple, there is no need to fit a guide ring on the top end of the cylindrical free-standing heater as in the past, and the strength against external forces from the side and top and bottom directions is suitably improved. This is an excellent improvement to the heating device used in presses.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the heater of the present invention.
2 is a sectional view taken along the line A-A in FIG. FIG. 4 is a perspective view of the heater. 6... Cylindrical self-supporting heater, 11... Convection promoting cylinder, 6c, 11c... Wall surface, 12, 13... Bent uneven surface.

Claims (1)

[Scope of utility model registration request] It consists of a pressure vessel to which a pressure medium is supplied by pressurized fluid, an upper cover and a lower cover that are removably fit tightly into the upper and lower opening ends of the vessel, and a cylindrical self-supporting type with a heat insulating layer interposed in the pressure vessel. In a heating device for a hot isostatic press in which a single-stage heater and a convection promoting cylinder are disposed, the wall surface extending in the vertical direction of the heater and the convection promoting cylinder has a cross section that is approximately chevron-shaped or corrugated. A heating device for a hot isostatic press, characterized in that the uneven curved surface is formed as a rigid reinforcing surface along the vertical direction.